Rheostat



Dec. 7 1926. 1,609,846

- J. F.TROY

RHEO S TAT Filed Jan. 20, 1923 WITNESSES: INVENTOR John F 770y ATTORNEY Patented Dec. 7, 1926. v

UNITED STATES JOHN F. TROY, OF ALLSTON, MASSACHUSETTS.

RHEOSTAT.

Application filed January 20,1923. Serial No. 613,812.

My invention relates to rheostats and the like, for controlling electrical circuits, and it has special relation to the'so-called filament rheostats for use in radio equipment.

One object of my invention is toprovide a rheostat. of the. above-indicated character which shall be relatively simple and inexw pensive in construction and effective and reliable in operation.

More specifically stated, it isanobject of myinvention to provide a rheostat for the purpose set forth above, embodying a plurality of resistor coils extending in side-byside relation, and preferably arranged in an are, together with a movable contact member for bridging the resistor coils.

Viewed from another angle, it is an object of my invention to provide a rheostat of the character in question wherein the movable contact member is adapted to be resiliently engaged by the inner sides of the resistor coils, the contact member thus being wedged along between the coils to provide the desired variation of circuit resistance.

Other objects of my invention will become evident from'the detailed description, taken in conjunction with the accompanying drawing, wherein-,-

igure'l is a view, in end elevation of a 'rheostatconstructed in accordance with my present invention, and

Fig. 2 is a side view of the apparatus shown in Fig. 1.

Referring to the drawings, the rheostat here shown comprises a cylindrical supporting member or disk 1 havin a plurality of peripheral grooves2, exten ing in side-by-,

side relation, for receiving a plurality of self-supporting resistor coils 3. I A movable contact member or arm 4 is supported by a pin or shaft 5 that extends centrally through the disk 1 and terminates, at one end, in a suitable knob 0r handle 6.

in position,

One end of the contact member or arm 4' is bent at right ang es and terminates in a Veshaped portion 4a that is located between, and is adapted to be resiliently engaged by, the inner or confronting sides ofthe two resistor coils 3.

. For the purpose of maintaining the coils I utilize a single small screw or bolt .7 that extends through a suitable opening near the periphery of the disk 1. The bolt 7 is adapted to secure in position a pair of metallic terminal members 8, to

which the corresponding confronting ends of the resistor coils are respectively attached to make suitable electrical connections and, at the same time, to secure in position a plurality of suitable insulating members 9 to which the opposite ends of the resistor coils are-hooked or otherwise attached. For convenient assembly, a rectangular boss or lug 10 may be provided in conjunction with the terminal members 8, insulating members 9 and the holding bolt 7.

The head of the bolt 7 may also serve as a stop member for the movable arm 4 in its two extreme positions. Tohold the contact arm 4: in its off position out of contact with the resistor coils themselves, the disk 1 may beprovided with a suitable boss or protuberance 11 upon'which the V-shaped' portion 4a re ts in such ofl position.

The operation "of my rheostat may be briefly set forth as follows:

Assuming that the contact arm t occupies its oif position, upon movement of the knob 6 the V-shaped portion 4a of the contact arm 4 is resiliently engaged by the inner sides of the resistor coils 3.. The V- corresponding to. the complete insertion of the two resistor coils, in series relation, in the electrical circuit being controlled, has been reached.

It will be seen that Ihave thus provided a relatively small and inexpensive rheostat that is particularly adapted for filament control in radio equipment and whereby a delicate and satisfactory-control of the filament currentmay be secured.

I do not wish to be restricted to the specific structural details or arrangement of parts herein set forth. as various modifications thereof may be effected without departing from the spirit and scope of my invention. I desire. therefore, that only such limitations shall be imposed as are indicated inthe appended claims.

I claim as my invention:

1. In a rheo tat, apair of coils extending in substantially parallel planes, and a single V-shaned contact member adapted to be wedged along between said coi s.

2. A rheostat comprising .a supporting member having a plurality of parallel extending grooves, a plurality of resistor coils disposed in said grooves, and a movable coniii) member having a plurality of parallel-ex tending peripheral grooves of substantially 7 equal inside diameters, a plurality of resistor coils disposed in said grooves, and a' movable contact member adapted to be resiliently engaged by adjacent sides of said coils.

4. A rheostat comprising a supporting member having a plurality of parallel-extending grooves. a plurality of resistor coils disposedin said grooves, and a V-shaped contact member adapted to be wedged along between said coils. a

5. In a-rheostat, a lurality of resistor coils extending in sidey -side relation, and arranged in arcs. of substantially equal diameter and a movable contact member for simultaneously engaging the inner sides of said coils,

6. In a rheostat, a plurality of resistor coils extending in side-by-side relation and arranged in arcs of substantially equal. diameter, and a V-shaped contact member adeipted to be wedged along between said cm s. I

7. A" rheostat comprising a cylindrical supporting member having a plurality of peripheral grooves, a plurality of resistor coils disposed in said grooves, and a movable contact member for simultaneously engaging the confronting sides of said coils.

8. A rheostat comprising a cylindrical supporting member having a plurality of peripheral grooves, a plurality of resistor coils disposed in said grooves, and'a movable contact member adapted to be resiliently engaged by the inner sides of said coils.

9. A rheostat comprising a cylindrical supporting member having a plurality of peripheral grooves, a plurality of resistor coils disposed in said grooves, and a V- shaped contact membenadapted to be wedged along between said coils.

10. A rheostat comprising a cylindrical supporting member having a plurality of peripheral grooves, a plurality of resistor coils disposed in said grooves, a plurality of conducting members secured to one set of ends of said coils, a plurality of insulating members secured to the other set of ends, and single means for securing said conducting members and said insulating members in position. I

11. A rheostat comprising a cylindrical supporting member having a plurality of peripheral grooves, a plurality of resistor coils disposed in said grooves,a rotatable pin extending axially through said supporting member, and a movable contact arm having one end secured to said pin and having its other end adapted to engage the inner sides of said coils.

12. A rheostat comprising a cylindric-Ll supporting member having a plurality f peripheral grooves, a plurality of resist r coils disposed in said grooves, a plurality of conducting members secured to one set of ends of said coils, a plurality of insulating members secured to the other set of ends, single means for securing said conducting members and said insulating members in position, and a movable contact arm having one end secured to said pin and having its other end adapted to engage the inner sides of said coils. r

13. In a rheostat, a plurality of resistor coilsiarranged in the form of a cylinder and haying substantially the same outside and inside diameters and extending in side-byside relation, and single contact means forconlcurrently engaging the inner sides of said cm s.

14. In a rheostat, a plurality of annularly disposed helices of conducting material having substantially the same diameter and extending in side-by-Side relation, single contact means for concurrently engaging con fronting sides of said coils, and means for relatively moving said helices and said contact means.

In testimony whereof, I have hereunto subscribed my name this 10th day of J anuary, 1923.

' JOHN F. TROY. 

